1. Field of the Invention
This invention relates to a printing machine having a detachable inker, more specifically to an improvement for easy attachment of an inker to a printing machine.
2. Description of the Related Art
A satellite-style web offset printing machine, for example, a Sammel printing press, generally has an inker which is movable and detachable with respect to the main printing unit.
A reason why such a detachable configuration is used is that the plate cylinder is necessary to be removed from the main unit at the time of printing pressure adjustment. Another reason is that the individual inking units in the inker must be independently driven for cleaning of inking rollers, ink feed, or nip width adjustment.
A drive mechanism of a prior art tricolor printing machine having a detachable inker will be briefly described with reference to FIG. 19. Referring to FIG. 19, in a printing machine main unit 1, a blanket cylinder 2 is supported on frames, and three plate cylinders 3 are disposed in contact with the outer peripheral surface of the blanket cylinder 2. At one axial end of each of plate cylinders 3 is integrally fixed a gear 4, and each gear 4 engages with a drive gear 5 to an inker 6.
The inker 6 is provided with inking units 7 of the same number as the plate cylinders 3. The individual inking units 7 are disposed according to the individual plate cylinders 3 so that when the inker 6 is attached to the main unit 1, a final inking roller 8 comes in contact with the printing plate surface of the individual plate cylinders 3 to feed ink.
In the inker 6, driven gears 9 of the same number as the plate cylinders 3 are supported on frames, and the individual driven gears 9 are connected to the individual inking units 7 via gears (not shown). These driven gears 9 are disposed relative to driving gears 5 so as to engage with the driving gears 5 when the inker 6 is attached to the main unit 1.
The inker 6 is placed on rotatable rollers 17 so that it can be moved to the right and left direction, and can be moved closer or farther relative to the main unit 1 by an inker moving device (not shown) using an actuator or by manual operation. Between the inker 6 and the main unit 1 is disposed a manual or actuator type fixing device (not shown).
Operation of the above printing machine will now be described. Suppose that the inker 6 is detached from the main unit 1. First, the inker 6 is moved manually or by the inker moving device forward to the vicinity of the main unit 1 where it is once stopped. Then, for positioning of the driving gears 5 and the driven gears 9, the teeth of both gears are aligned visually by the operator and the inker 6 is moved forward until the gears 5 and 9 come to engagement. With this condition, the fixing device is operated manually or by the actuator to fix the inker 6 to the main unit 1.
When printing operation is performed, a motor (not shown) of the main unit 1 is operated to rotate the blanket cylinder 2, the individual plate cylinders 3, and the individual driving gears 5. This causes the driving gears 5 to rotate the corresponding driven gears 9, the inking rollers 8 of the individual inking units 7 are rotated, and ink is supplied from the individual inking rollers 8 to the printing plate surface of the corresponding plate cylinders 3, thus making printing from the blanket cylinder 2 to paper.
To remove the inker 6 from the main unit 1, both units are unlocked, and then the inker 6 is moved to a predetermined withdrawal position.
In the prior art movable inker type printing machine, when the inker 6 is attached to the printing machine main unit 1, phase alignment between the driving gears 5 and the driven gears 9 must be made visually, thus involving very poor workability. Due to such visual operation, gear engagement may sometimes be poor, which lead to damages to the gears 5 and 9.
Furthermore, there must be provided an open space around the gears 5 and 9 for visual operation, an oil shower lubrication system cannot be used for the mechanism.
In addition, due to the visual operation, attachment of the inker 6 to the printing machine main unit 1 cannot be automated.